<?hh <<__EntryPoint>> function main(): void {
$first = "boo";
$second = $first;
$rot = "";

echo "1: ".$first."\n";
echo "2: ".$second."\n";
echo "3: ".$rot."\n";

$rot = str_rot13($second);

echo "1: ".$first."\n";
echo "2: ".$second."\n";
echo "3: ".$rot."\n";
}
